title: Lipoxygenase activity in rat kidney glomeruli, glomerular epithelial cells, and cortical tubules.
abstract: We examined the possibility that renal glomerular and cortical tubular tissue has lipoxygenase activity in addition to the well established cyclo-oxygenase pathway of arachidonic acid metabolism. Homogenized rat kidney glomeruli, in the presence of meclofenamate (33 microM) and divalent cation ionophore A23187 (3 microM), metabolized octatritiated arachidonic acid to 12-hydroxyeicosatetraenoic acid and lesser amounts of 80 and/or 9-hydroxyeicosatetraenoic acid. These products were identified by thin layer chromatography, high performance liquid chromatography, and gas chromatography-mass spectroscopy. In order to rule out the synthesis of hydroxylated fatty acids by platelets and leukocytes entrapped in the glomeruli, we studied lipoxygenase products in glomerular epithelial cells after 9 days in cell culture. Homogenized glomerular epithelial cells converted octatritiated arachidonic acid to 12-hydroxyeicosatetraenoic acid solely. The lipoxygenase activity in cortical tubules was substantially less than in glomeruli and only 12-hydroxyeicosatetraenoic acid was synthesized. The production of hydroxyeicosatetraenoic acid by lipoxygenase inhibitors, nordihydroguaiaretic acid, 5,-homogenized glomeruli, glomerular epithelial cells, and cortical tubules was inhibited by three 8,11,14-eicosatetraynoic acid, and 1-phenyl-3-pyrazolidone. These data demonstrate that there is lipoxygenase activity in rat kidney glomeruli, glomerular epithelial cells and to a lesser extent cortical tubules, and may imply a role of the lipoxygenase products in the regulation of normal glomerular function and inflammatory disease of the kidney.
mesh_terms: D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D004848:Epithelium / Q000201:enzymology; D005260:Female; D007672:Kidney Cortex / Q000201:enzymology*; D007678:Kidney Glomerulus / Q000201:enzymology*; D007684:Kidney Tubules / Q000201:enzymology*; D007700:Kinetics; D008084:Lipoxygenase / Q000302:isolation & purification / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000001:Calcimycin; D008084:Lipoxygenase